A few prior ovens are shown in U.S. Pat. Nos. 3,665,842; 3,809,859; 4,008,996; 4,044,660; 4,134,005; 4,226,176; 4,245,613; 4,386,558; 4,366,177; 4,664,923; 4,465,701; 5,197,375; 5,253,564 and 5,473,975, and Canadian Patent 1,041,148.
There are many large and sophisticated conveyor ovens weighing hundreds, and sometimes a thousand or more, of pounds with expensive controls. However, such sophistication has not extended to the small toaster/oven size, which has a relatively low cost as compared to the cost of the large oven. For commercial installations the toaster/oven size has a length in the nature of two or three feet and a width of, perhaps, a foot and a half.
A desirable toaster/oven has a flexible design wherein a manufacturer provides a plurality of appliances which meet a variety of customer requirements without requiring any appreciable redesign or change of tooling or production procedures. Examples of the various customer requirements are: toasting high or tall products (such as muffins), medium height products (such as bagels), and low height products (such as bread slices), and baking a great variety of products.
The term "Hearth Baking" is often applied to a type of baking where a heat sink (such as a flat stone) is first heated in an oven to a fairly high temperature and then a food product (such as a pizza) is placed on the heat sink. There is a fast cooking or baking action at the area of contact between heat sink and food product followed by complete cooking in the oven.
Another need is to provide a small conveyor toaster/oven, of a single general size and design, but with a capability by which the manufacturer may select between toasting and hearth baking without requiring a substantial amount of redesign, tooling, or the like. It would also be desirable to provide a toaster/oven with a single and flexible design which can be made larger or smaller, to use an open wire link conveyor belt or a tightly woven herringbone belt, and to toast or hearth bake.
Also, on an occasion, perhaps a full load of food products filling the entire conveyor passes through the oven to soak up a substantial amount of heat during the toasting, cooking, or hearth baking process. On another occasion, perhaps a half load or only a few food products pass through the oven to soak up a small amount of heat during the process. Hence, there should be some way of adjusting both the amount and the nature of heat that is produced along with the speed at which food is conveyed through the oven.
U.S. Pat. No. 5,473,975 shows and describes an open link wire conveyor belt made of relatively widely spaced parallel wires. The heat passes through the open spaces between the wires which have only a minimum, if any effect, upon the food product.
There is another kind of food product, such as a grilled cheese sandwich, for example, which is best if prepared or hearth baked on a griddle, such as a tightly woven herringbone hearth belt. If these and similar food products are cooked on a conventional griddle, someone has to more or less continuously observe them and remove them when done. This personal attention is not very efficient, especially for fast food restaurants, and often leads to variations in the final food product. It would be far better if the raw food product can be placed on one end of a conveyor and a fully and uniformly prepared product can be removed from the other end of the conveyor. Then, there would be no need for constant supervision. The end products would be uniformly grilled or hearth baked.
Accordingly, an object of the invention is to provide new and improved conveyor ovens of the described type. Here, an object is to provide ovens which grill or hearth bake while responding to and overcoming the above stated and similar problems.
Another object of the invention is to provide new and improved toaster size, commercial conveyor ovens having a griddle-like surface. Yet another object is to provide such a multi-purpose conveyor toaster/oven having a relatively small size.